It is known to provide both pressurized fluid dispensers, and non-pressurized fluid dispensers which dispense fluid through a nozzle arrangement, and which may include a dip tube connected to the nozzle arrangement, through which fluid is dispensed.
Nozzle arrangements are commonly used to facilitate the dispensing of various fluids from containers or vessels. For instance, nozzle arrangements are commonly fitted to pressurized fluid filled vessels or containers, such as an aerosol canister, to provide a means by which fluid stored in the vessel or container can be dispensed. In addition, so called pump and trigger activated nozzle arrangements are also commonly used to enable the fluid contents of a non pressurized vessel or container to be conveniently dispensed in response to the operation of the pump or trigger by an operator. Another version that is much less commonly used uses a pump or trigger to pressurize the air and fluid inside the container and this pressure can be topped up as the fluid is used up. This effectively becomes the same as an aerosol canister in use.
A typical nozzle arrangement comprises an inlet through which fluid accesses the nozzle arrangement, an outlet through which the fluid is dispensed into the external environment, and an internal flow passageway through which fluid can flow from the inlet to the outlet. In addition, conventional nozzle arrangements comprise an actuator means, such as, for example, a manually operated pump or trigger or aerosol canister. The operation of the actuator means causes fluid to flow from the container to which the arrangement is attached into the inlet of the arrangement, where it flows along the fluid flow passageway to the outlet.
Many liquors, foams or pastes are delivered using manually operated aerosol cans, pumps or triggers and they often have a diptube reaching from the top or outlet of the container to the bottom so that the fluid is drawn from the bottom to the top and out through the outlet. Sometimes these diptubes are part of the container and can be in the centre of the container or along a wall of the container especially with plastic containers. A large number of commercial products can be dispensed this way, including, for example, tooth paste, antiperspirants, de-odorants, perfumes, air fresheners, antiseptics, paints, insecticides, polish, hair care products, pharmaceuticals, shaving gels and foams, water and lubricants.
Most fluids are simply held in the container with air taking up the remainder of the container with pumps or triggers and air or a propellant taking up the remainder of the container for aerosols or pressurized containers. This is no problem for most fluids but some need to be kept separate from the air or in the case of aerosol canisters from the pressurized propellant which may be air or butane or other alternatives like CO2. Some products like foods can go off and others like shaving gel can expand and become either unusable or unstable. This also prevents accidental loss of the air or propellant when the device is used and this can be a problem.
The problem of separating the fluid from the air or propellant has been generally approached in two different ways. In aerosol cans deformable bags are used in can or via bags attached to valves. The fluid is kept in a bag inside the canister and the bag is either sealed around part of the can itself or around the valve in the can and the propellant gas is inside the can and around the bag. When the outlet valve is opened by depressing the actuator, the gas pressure acting on the bag forces out the fluid through the valve and actuator and the bag is compressed. The bags are often made of up to 4 different layers of material so as to keep the propellant and fluid apart and they are relatively expensive and the assembly process is generally expensive and complicated. The bags often never completely empty the contents and 5-10% of the fluid tends to remain in the bag.
With pumps and triggers bags are also sometimes used and another approach has been to use a shaped plate between the fluid and air called “follower plates” as they follow the fluid as the container empties. These plates seal against the side walls of the container and are upstream of the fluid in the container usually towards the base. As the fluid is discharged, the plate moves downstream keeping the fluid chamber filled. For this to work the walls of the container have to be parallel and the vessel is usually tubular or oval in shape. The plate is usually shaped to match the shape of the downstream end or top of the container so as to be able to drive most or substantially all of the fluid out of the container. If the top of the container is shaped like a standard bottle or container with a reduced neck on the shoulder then the bottom of the chamber has to be open so the follower plate can be inserted through the bottom. Alternatively, with a closed bottom the top of the container has to be the same size and shape as the rest of the container so the follower plate can be inserted from the top.
Advantages of follower plates include that they are relatively cheaper to make and assemble than other means described hereinabove. One disadvantage is that they cannot be used with diptubes or inside aerosol cans or with bottles or containers with smaller necks and a closed base.
Bags are widely used in pump or trigger containers and they can be a separate bag that is inserted after the container is made or they can be moulded into the container. The fluid is put inside the bag and is delivered by being sucked out of the bag by the pump or trigger collapsing the bag. Air is drawn into the container through a hole or aperture in the container wall or top and then around the bag as the bag is collapsed and the air is at atmospheric pressure. Sometimes the bag is made of one plastic or rubber and other times it is made of layers of different materials depending upon the barrier properties required to protect the fluid. These systems are generally more expensive than follower plates although they may be more versatile and standard containers can be used. Bags tend to be made of layers because they are thin whereas a follower plate tends to be thicker and made of a stronger, more chemically resistant plastic creating robust barrier.
There are two general types of aerosol cans with one having a seam along the length of the can and a separate top and bottom joined to the body and the other being seamless and made from one part which is drawn into shape and a separate top joined to the body. Known follower plates would not work with seamed containers as there would be no seal because of the seam. In seamless cans with reduced neck diameters it is not possible to use a follower plate because of the reduced neck preventing insertion of the plate and another problem with aerosol cans comprising diptubes is that any diptube present would be in the way of the follower plate.
It is therefore an aim of embodiments of the invention to provide fluid dispensers which enable separation of at least some of the air/gas or propellant in a dispenser from the dispensing liquid and which prevent or reduce leakage of the air/gas or propellant into a diptube or out of the dispenser. It is also an aim of embodiments of the invention to provide divider or fluid reservoirs for us in fluid dispensers which can be used in a wide variety of dispensers and which are robust, relatively inexpensive to make an insert, and which can be inserted into a wide variety of fluid dispensers including seamed dispensers, dispensers with reduced diameter necks and aerosols or other pressurized containers.
It is also an aim of embodiments of the invention to overcome or mitigate at least one problem of the prior art described herein above.